Buggy code:
public class CompletionParser extends AssistParser { protected static final int COMPLETION_PARSER = 1024 ; protected static final int COMPLETION_OR_ASSIST_PARSER = ( AssistParser . ASSIST_PARSER ) + ( CompletionParser . COMPLETION_PARSER ) ; protected static final int K_BLOCK_DELIMITER = ( CompletionParser . COMPLETION_PARSER ) + 1 ; protected static final int K_SELECTOR_INVOCATION_TYPE = ( CompletionParser . COMPLETION_PARSER ) + 2 ; protected static final int K_SELECTOR_QUALIFIER = ( CompletionParser . COMPLETION_PARSER ) + 3 ; protected static final int K_BETWEEN_CATCH_AND_RIGHT_PAREN = ( CompletionParser . COMPLETION_PARSER ) + 4 ; protected static final int K_NEXT_TYPEREF_IS_CLASS = ( CompletionParser . COMPLETION_PARSER ) + 5 ; protected static final int K_NEXT_TYPEREF_IS_INTERFACE = ( CompletionParser . COMPLETION_PARSER ) + 6 ; protected static final int K_NEXT_TYPEREF_IS_EXCEPTION = ( CompletionParser . COMPLETION_PARSER ) + 7 ; protected static final int K_BETWEEN_NEW_AND_LEFT_BRACKET = ( CompletionParser . COMPLETION_PARSER ) + 8 ; protected static final int K_INSIDE_THROW_STATEMENT = ( CompletionParser . COMPLETION_PARSER ) + 9 ; protected static final int K_INSIDE_RETURN_STATEMENT = ( CompletionParser . COMPLETION_PARSER ) + 10 ; protected static final int K_CAST_STATEMENT = ( CompletionParser . COMPLETION_PARSER ) + 11 ; protected static final int K_OPERATOR = ( CompletionParser . COMPLETION_PARSER ) + 12 ; public int cursorLocation ; public AstNode assistNodeParent ; static final int EXPLICIT_RECEIVER = 0 ; static final int NO_RECEIVER = - 1 ; static final int SUPER_RECEIVER = - 2 ; static final int NAME_RECEIVER = - 3 ; static final int ALLOCATION = - 4 ; static final int QUALIFIED_ALLOCATION = - 5 ; int invocationType ; int qualifier ; int lastModifiers = AccDefault ; int lastModifiersStart = - 1 ; int bracketDepth ; public CompletionParser ( ProblemReporter problemReporter , boolean assertMode ) { } public char [ ] assistIdentifier ( ) { } protected void attachOrphanCompletionNode ( ) { } private void buildMoreCompletionContext ( Expression expression ) { int i = 0 ; int kind = - 1 ; nextElement : while ( ( ( kind = topKnownElementKind ( CompletionParser . COMPLETION_OR_ASSIST_PARSER , i ) ) != ( CompletionParser . K_BLOCK_DELIMITER ) ) && ( kind != 0 ) ) { int info = topKnownElementInfo ( CompletionParser . COMPLETION_OR_ASSIST_PARSER , i ) ; switch ( kind ) { case AssistParser . K_SELECTOR : if ( ( info == ( AssistParser . THIS_CONSTRUCTOR ) ) || ( info == ( AssistParser . SUPER_CONSTRUCTOR ) ) ) { ExplicitConstructorCall call = new ExplicitConstructorCall ( ( info == ( AssistParser . THIS_CONSTRUCTOR ) ? ExplicitConstructorCall . This : ExplicitConstructorCall . Super ) ) ; call . arguments = new Expression [ ] { expression } ; call . sourceStart = expression . sourceStart ; call . sourceEnd = expression . sourceEnd ; assistNodeParent = call ; } else { int invocationType = topKnownElementInfo ( CompletionParser . COMPLETION_OR_ASSIST_PARSER , ( i - 1 ) ) ; int qualifierExprPtr = topKnownElementInfo ( CompletionParser . COMPLETION_OR_ASSIST_PARSER , ( i - 2 ) ) ; int length = expressionLengthStack [ expressionLengthPtr ] ; if ( ( ( expressionLengthPtr ) > 0 ) && ( length == 1 ) ) { int start = ( ( int ) ( ( identifierPositionStack [ info ] ) > > > 32 ) ) ; <START_BUG> if ( ( this . expressionStack [ ( ( expressionPtr ) - 1 ) ] . sourceStart ) > start ) { <END_BUG> length += expressionLengthStack [ ( ( expressionLengthPtr ) - 1 ) ] ; } } Expression [ ] arguments = null ; if ( length != 0 ) { arguments = new Expression [ length ] ; expressionPtr -= length ; System . arraycopy ( expressionStack , ( ( expressionPtr ) + 1 ) , arguments , 0 , ( length - 1 ) ) ; arguments [ ( length - 1 ) ] = expression ; } if ( ( invocationType != ( CompletionParser . ALLOCATION ) ) && ( invocationType != ( CompletionParser . QUALIFIED_ALLOCATION ) ) ) { MessageSend messageSend = new MessageSend ( ) ; messageSend . selector = identifierStack [ info ] ; messageSend . arguments = arguments ; switch ( invocationType ) { case CompletionParser . NO_RECEIVER : messageSend . receiver = ThisImplicit ; break ; case CompletionParser . NAME_RECEIVER : while ( ( ( this . identifierLengthPtr ) >= 0 ) && ( ( this . identifierLengthStack [ this . identifierLengthPtr ] ) < 0 ) ) { ( this . identifierLengthPtr ) -- ; } ( this . identifierPtr ) -- ; ( this . identifierLengthStack [ this . identifierLengthPtr ] ) -- ; messageSend . receiver = this . getUnspecifiedReference ( ) ; break ; case CompletionParser . SUPER_RECEIVER : messageSend . receiver = Super ; break ; case CompletionParser . EXPLICIT_RECEIVER : messageSend . receiver = this . expressionStack [ qualifierExprPtr ] ; break ; default : messageSend . receiver = ThisImplicit ; break ; } assistNodeParent = messageSend ; } else { if ( invocationType == ( CompletionParser . ALLOCATION ) ) { AllocationExpression allocationExpr = new AllocationExpression ( ) ; allocationExpr . arguments = arguments ; allocationExpr . type = getTypeReference ( 0 ) ; assistNodeParent = allocationExpr ; } else { QualifiedAllocationExpression allocationExpr = new QualifiedAllocationExpression ( ) ; allocationExpr . enclosingInstance = this . expressionStack [ qualifierExprPtr ] ; allocationExpr . arguments = arguments ; allocationExpr . type = getTypeReference ( 0 ) ; assistNodeParent = allocationExpr ; } } } break nextElement ; case CompletionParser . K_INSIDE_RETURN_STATEMENT : if ( info == ( bracketDepth ) ) { ReturnStatement returnStatement = new ReturnStatement ( expression , expression . sourceStart , expression . sourceEnd ) ; if ( expression == ( assistNode ) ) { assistNodeParent = expression ; } assistNodeParent = returnStatement ; } break nextElement ; case CompletionParser . K_CAST_STATEMENT : Expression castType ;

Fix:
if ( ( ( this . expressionStack [ ( ( expressionPtr ) - 1 ) ] ) != null ) && ( ( this . expressionStack [ ( ( expressionPtr ) - 1 ) ] . sourceStart ) > start ) ) {